i would of used like 500grams of caustic soda and really warm water. gotta use it a metal or plastic tub as it will eat thru the foam and your toes in about 2 mins :blinks:
edit - caustic soda will also remove the rust! just remove all the bearings/anything alloy beforehand
edit agian - oven cleaner also has caustic soda in it so just buy some of that, spray and leave for a hour then rise off